For a water storage dam, the intake is the contact between said water storage dam and the irrigation zone, hence the importance of the intake; If it were to be obstructed, the dam and the irrigation zone thereof would be unusable, because it is an area that is typically submerged, making it difficult to repair. The rains cause river and stream runoff, that besides the water, drag solids such as gravel and erosion-produced sand, the path of said materials ending up at the vessel of the storage dam, where it begins decantation and sedimentation as the water stagnates; in this process, the solids in suspension are deposited at the bottom of the dam and, throughout the years, it produces considerable volumes of what is known as sedimentary deposit. This, however, is an expected outcome in all projects; a use life of 50 or 60 years is also generally estimated. This circumstance is a major problem which has different solutions, all at considerable cost, same which are outlined below:
Option 1
Build a new dam
Notes
Too costly, generally not feasible, in addition to having been built 50 or 60 years ago; Therefore, it occupies the best topographic and geological site in the vicinity of the region to be benefited. Furthermore, it should be noted that the infrastructure of the irrigation zone, often thousands of hectares, would become useless.
Option 2
Build a new intake, including the floodways, up to the irrigation zone.
Notes
Likewise very costly and not advisable, the topographic characteristics of each case must be considered, frequently the floodway is designed by drilling tunnels through the hillside.
Option 3
Repair the intake.
Notes
This is the most feasible option, however, it is also very costly, since the cofferdam system (large tubes driven into the sedimentary deposit) is used to form a structure that withstands the thrust force of the water, when draining the internal area of the structure thus formed, generally double-squared dimensions according to the particular needs of the project, filling up the area between the double square to provide stability. Work cannot begin until the internal area of the structure is drained first.
The present invention uses an entirely different method than the methods already known, since it does not use cofferdams, the present invention when using a modular cabin to isolate the work area, and when employing divers to perform the works inside the dam with the decantation systems, make for the intake repair work to be shorter time and more efficiently than the aforementioned options.